The present application is related to the following commonly-owned U.S. Patent Applications filed concurrently herewith, and which are hereby incorporated by reference in their entirety:
(1) U.S. patent application Ser. No. 11/821,425, now U.S. Pat. No. 7,597,229, entitled END EFFECTOR CLOSURE SYSTEM FOR A SURGICAL STAPLING INSTRUMENT;
(2) U.S. patent application Ser. No. 11/821,426, now U.S. Pat. No. 7,604,150, entitled SURGICAL STAPLING INSTRUMENT WITH AN ANTI-BACK UP MECHANISM;
(3) U.S. patent application Ser. No. 11/821,347, now U.S. Pat. No. 7,441,685, entitled SURGICAL STAPLING INSTRUMENT WITH A RETURN MECHANISM;
(4) U.S. patent application Ser. No. 11/821,455, now U.S. Pat. No. 7,549,564, entitled SURGICAL STAPLING INSTRUMENT WITH AN ARTCULATING END EFFECTOR; and.
(5) U.S. patent application Ser. No. 11/821,277, now U.S. Pat. No. 7,753,245, entitled SURGICAL STAPLING INSTRUMENTS.
1. Field of the Invention
The present invention generally relates to surgical stapling instruments and, more particularly, to surgical staplers having a closing system which allows for closing of an end effector and allows for an automatic controlled opening of the end effector.
2. Description of the Related Art
As known in the art, surgical staplers are often used to deploy staples into soft tissue in order to reduce or eliminate bleeding from the soft tissue, especially as the tissue is being transected, for example. Surgical staplers, such as an endocutter, for example, can comprise an end effector which can be moved, or articulated, with respect to an elongate shaft assembly. End effectors are often configured to secure soft tissue between first and second jaw members where the first jaw member often includes a staple cartridge which is configured to removably store staples therein and the second jaw member often includes an anvil. Such surgical staplers can include a closing system for pivoting the anvil relative to the staple cartridge.
Staples are typically deployed from the staple cartridge by a driver which traverses a channel in the staple cartridge and causes the staples to be deformed against the anvil and secure layers of the soft tissue together. Often, as known in the art, the staples are deployed in several staple lines, or rows, in order to more reliably secure the layers of tissue together. The end effector may also include a cutting member, such as a knife, for example, which is advanced between two rows of the staples to resect the soft tissue after the layers of the soft tissue have been stapled together.
After the driver and the cutting member have been advanced within the end effector, it is often necessary to retract the driver and/or cutting member to their starting positions and release the first and second jaw members of the end effector. Often surgical staplers have included an opening spring which returns a closure trigger to the closure trigger's open position thus returning the first and second jaw members to their original positions after a release button or toggle switch on the surgical stapler has been actuated by the surgeon, for example. Such staplers, however, are often difficult to use as such opening springs often apply a biasing force to the closure trigger which can, in various circumstances, cause the closure trigger to open and thus the first and second jaws of the end effector to automatically spring open with excessive force which may damage tissue surrounding the end effector. What is needed is an improvement over the foregoing.